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Old 02-25-2019, 02:50 AM   #12
Mike Meier
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Join Date: Dec 2001
Location: Webster, TX
Posts: 317
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Default Re: Chevy Cobalt DF/S and maybe keep it streetable

Quick update:

Unfortunately the test and tune night at Houston Raceway Park this past Friday was rained out so I haven't had the chance to make a full quarter mile pass with most of the modifications; but the local brackets are eighth mile and I have gone as quick as a 9.96 at 69.11 MPH.

A good number of my eighth mile passes were in 3 to 4 hundredth spreads with each respective major change.

Done:

Slicks, front runners, and light weight rims
Mid-length header (1.5 inch primaries, 2.5 inch collector) and down-pipe with 400 cell catalytic converter
Removed upper intake manifold and just running open throttle body (though car is now throwing DTC for the MAF Sensor
Fuel sample valve had been installed
Best run was at 2,850 LBS running 93 octane

Have not done:

Did not flash the ECU with HP Tuners. Walt Walker made some changes to the tune related to when the cooling fan comes on and how much torque is applied (he did not mess with any fuel related tables); it would not sync up properly as it was not recognizing the credits that I purchased with the device. As soon as I can get tech support to resolve the issue, I'm flashing the computer.

Need to drain the remaining 93 octane from the fuel tank, change the fuel filter, and replace with Sunoco 260 GTX. For the record, attempting to run a car that gets 28 MPG until it runs out of fuel is such a pain in the butt. I drove the 30 miles home from Baytown with the Low Fuel warning hoping it would run out of gas so I could dump in the race fuel to make it the rest of the way home.

When the mechanic across the street installed the header and down pipe, he hooked it into the stock exhaust, so I need to open things up a little.

Going to buy a tow vehicle on Monday because the Suburban crapped out in December. Need to get that inspected and registered by Wednesday so I can high-tail it out to No Problem Raceway's Thursday Test and Tune to try and get this car under the index.
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Mike Meier
"World's most expensive DF/S" 2007 Chevy Cobalt....because suffering through owning an AMC Stocker wasn't enough
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